High vertical lift bridge

ABSTRACT

THE INVENTION IS A VERTICAL LIFT BRIDGE WHICH IS RAISED UTILIZING HYDRAULICALLY DRIVEN PISTONS. IN ORDER THAT THE BRIDGE MAY BE RAISED TO A SUBSATANTIALLY HEIGHT, THE HYDRAULIC DRIVE SYSTEM IS ARRANGED TO RAISE THE BRIDGE IN A SERIES OF STEPS. THUS, EACH HYDRAULIC DRIVE MOTOR OPERATES ON A VERTICAL RAIL OR CHANNEL USING RELEASABLE GRIPPING SHOES   WHICH PERMITS THE DRIVE CYLINDER TO BE FULLY EXTENDED A NUMBER OF TIMES SO THAT THE BRIDGE MAY BE RAISED TO A HEIGHT EQUAL TO MULTIPLES OF THE STROKE OF THE HYDRAULIC DRIVE MOTOR.

March 16, 1971 E. F. ALLEN 3,570,032

HIGH VERTICAL LIFT BRIDGE Filed March 7, 1969 4 Sheets-Sheet 1 Anne/say March 16, 1971 Filed March 7, 1969 E. F. ALLEN HIGH VERTICAL LIFT BRIDGE FT-i s.

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HIGH VERTICAL LIFT BRIDGE 4 Sheets-Sheet 5 y m M 4 M a m 6/ s w n w h n d m i @ZZ/ \w a M 1 5 y 5 6 7. M 10 i m 7////////O/// A m /w//////////// 475% /l L w 5 m 7 Q w M fi F. .Ft. .1; 5 TILEEIKL March 16, 1971 Filed March '7, 1969 March 16, 1971 F, ALLEN 3,570,032

HIGH VERTICAL LIFT BRIDGE Filed March '7, 1969 4 Sheets-Sheet 4 [H INVENTOR. 5412:.5 F flue Y T 14 70/QIYC) United States Patent 3,570,032 HIGH VERTICAL LIFT BRIDGE Earle F. Allen, Plymouth, Mass, assignor to Valentine E. Macy, Jr., New York, N.Y., a fractional part interest Filed Mar. 7, 1969, Ser. No. 806,044 Int. Cl. E01d /02 US. CI. 14-42 5 Claims ABSTRACT OF THE DISCLOSURE The invention is a vertical lift bridge which is raised utilizing hydraulically driven pistons. In order that the bridge may be raised to a substantial height, the hydraulic drive system is arranged to raise the bridge in a series of steps. Thus, each hydraulic drive motor operates on a vertical rail or channel using releasable gripping shoes which permits the drive cylinder to be fully extended a number of times so that the bridge may be raised to a height equal to multiples of the stroke of the hydraulic drive motor.

BRIEF SUMMARY OF THE INVENTION This invention relates to a hydraulic drive system for raising structures such as bridge spans. It is adapted to employ relatively powerful yet simple hydraulic drive cylinders for the lifting force. In order that the structure may be raised to a relatively substantial height which may be several times greater than the driving stroke of the drive pistons, a clamping arrangement is provided whereby each of the lifting motors is fully extended and then is drawn back for an additional lifting cycle while the bridge remains clamped at its raised position. In order to provide a fail-safe operation both for the drive motors and for the clamps, the clamps and brake members for the drive motor drive members are spring loaded to grip their cooperating supports or pistons in the absence of hydraulic pressure and to be released only when proper hydraulic pressure is applied. This arrangement insures that hydraulic pressure will always be available in the lifting pistons when the span is released for movement by the hydraulic drive pistons.

The bridge or other structure, therefore, may be moved a substantial distance where the drive cylinders themselves are relatively compact as the lifting action is performed by a series of successive extensions of the hydraulic drive cylinder pistons combined with novel fail-safe braking steps.

Accordingly, the object of the invention is to provide an improved hydraulic drive system for lift bridges.

Another object of the present invention is to provide a compact, powerful, and reliable hydraulic lift means for a bridge span or similar structure which includes failsafe locking arrangements to support the bridge structure at any position in the event of a loss of hydraulic drive pressure.

Another object of the present invention is to provide a hydraulically operated drive system of relatively compact form capable of raising a bridge span a substantial distance.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention has been choosen for purposes of illustration and is shown in the following drawings wherein:

3,570,032 Patented Mar. 16, 1971 FIG. 1 is a perspective view partial in section illustrating a bridge span having hydraulic lifting means in accordance with the present invention;

FIGS. 2, 3, and 4 are diagrammatic illustrations of the hydraulic lifting means illustrating its step-by-step action;

FIG. 5 is an enlarged detailed side elevational view of the hydraulic drive means in accordance with the present invention;

FIG. 6 is a front elevational view of the drive means of FIG. 5;

FIG. 7 is an enlarged detailed side elevational view partial in section showing a support rail and drive piston braking or clamping members;

FIG. 8 is a horizontal sectional view taken along line 88 on FIG. 7;

FIG. 9 is a front elevational view partial in section illustrating another embodiment of the span drive braking means;

FIG. 10 is a horizontal sectional view of the braking means of FIG. 9; and

FIG. 11 is a side elevational view of the braking means of FIG. 9.

DETAILED DESCRIPTION FIG. 1 illustrates a typical horizontal bridge span for bridging a body of water or other space and which must periodically be raised to provide a substantial clearance. Such a span might be used, for example, in bridging a river or canal where the span is periodically raised or to clear traffic.

The span in accordance with the present invention is raised by means of hydraulic lift mechanisms attached to the span as, for example, at the four corners of the span 1 as illustrated in FIG. 1. In the position illustrated in FIG. 1, the span 1 is at its fully lowered position resting against permanent seats 2 and in position for supporting traffic or other loads. Hydraulic lift means in accordance with the present invention are provided to raise this span and as will be described below, these lift means permit the span 1 to be raised to almost any height desired by a step-by-step or repeated lifting action.

In FIG. 1, four vertical support posts 3 or other members such as regular bridge counterweight towers are provided each of which has attached thereto a relatively strong elongated clamping rail 4 such as an iron or steel rail or other member. Each of the rails 4 is shown to be slideably engaged by two guide shoes and gripping brakes 5 and 6 one of which 5 is attached to the end of the drive cylinder piston 7 and the other of which 6 is fixedly attached to the span 1 itself.

This step-by-step or repeated lifting action is diagrammatically illustrated in FIGS. 2, 3 and 4. These figures show the vertical rails 4 slideably engaging the span brake 6 and the lifting brake '5 attached to the lower end of the hydraulic piston rod 7. FIG. 1 shows the span 1 at its lowermost position at the beginning of the lifting action. In this position, the piston brake 5 is engaged with the support rail 4 to temporarily tightly couple the piston rod 7 end to the rail 4. The span brake 6 has been released from span 1 as the hydraulic drive cylinder 8 lowers its piston 7 in the manner illustrated in FIG. 3. In FIG. 3, the piston rod 7 is fully extended and the span 1 has now been raised a distance equal to the length of piston travel. In FIG. 4, the span brake 6 is now applied locking the span 1 in its raised position while the piston brake 5 is released permitting the piston 7 to be raised preparatory to another lifting cycle.

The lifting cycle may be repeated as many times as desired to lift the span I to the desired height. It is clear from the above description that the height that the bridge span 1 is raised may be controlled so that on some occasions the span need only be lifted through one cycle to clear a relatively low object and so that the bridge span 1 may be lifted to a much greater height where necessary. The only additional equipment required for providing this additonal upward movement is the upwardly extending support rails 4 together with a stabilizing means or mounting post for the rails 4 which in many cases is already available in the form of counterweight or other posts.

FIGS. 5 and 6 illustrate a preferred arrangement of a hydraulic lifting cylinder 8 attached to a bridge span 1 of typical weight and portions. A hydraulic drive cylinder 8 such as that illustrated in these figures may be furnished in a suitable length to give significant span clearance in a single lifting cycle and at the same time to have a reasonably compact overall size to facilitate the manufacture of a relatively inexpensive and reliable and easily handled drive cylinder. Typical cylinders for this application might form from a few feet to cylinders as much as 15 or 20 feet in length or more depending upon the particular system. The clamping brake 5 is illustrated in solid lines at the lower end of the drive piston 7 engaging the surface of the support rail 4. The span brake 6 which may be generally similar design, as will be more fully described below, is mounted on a convenient support flange 10 directly to the bridge span 1. The span 1 is shown in dash-dot lines in FIGS. 5 and 6 after being raised by one operation of the cylinder 8. At this position brake 6 is engaged and brake 5 is released so that piston rod 7 may be lowered for the next cycle.

Since hydraulic power is available in the drive system for extending the cylinder piston rods 7, this same hydraulic force is also effectively used for the operation of the piston brake 5 and the span brake 6. Additionally, particularly in view of the importance of the braking action during the span raising and during the raised span period, a reliable braking force must be used to engage the two brakes 5 and 6 with the support rail 4.

FIGS. 7 and 8 illustrate a preferred and particularly desirable embodiment of a brake of the fail-safe type for use in the above described lifting arrangement.

FIG. 7 illustrates one of the hydraulic drive cylinders 8 with its piston rod 7 attached to the lowed brake 5. A piston rod brake 12 is shown positioned between the brake 5 and the lower end of the drive cylinder 8. This brake 12 is adapted to lock the piston 7 at any point of its travel and in its preferred form it is a fail-safe brake. The fail-safe operation is obtained by having the braking force applied to the brake 12 by a spring means such as a compressed coil spring 13 acting against a hydraulically operated piston 14. Whenever the hydraulic pressure fails or is reduced in chamber 11 below an effective operating pressure, the spring 13 moves the piston 14 upwardly thereby applying a braking force through the intermediation of the complementary tapered conical surfaces 15 of the braking piston 14 and 16 the brake shoe 17. A preferred form of this brake 12 as well as other suitable brakes are illustrated in my issued US. Pat. No. 3,203,513 dated Aug. 31, 1965.

As illustrated schematically in FIG. 2, the hydraulic portion of the brake 12 is coupled to the hydraulic line 18 feeding the underside of the drive cylinder 8 by line 19. This portion of the cylinder 8 will be subjected to hydraulic pressure from the hydraulic pump 20 when the bridge span 1 is being raised and will also be under hydraulic pressure from the weight of the bridge span 1 during the bridge lowering operation. It is, therefore, clear that while the bridge span 1 is being raised or lowered under normal operating conditions that the brake 12 will be held in a released position by downward movement of the brake piston 14. When hydraulic pressure is cut off at the span raising or lowering or if the hydraulic pressure fails for any other reason such as by a line failure, the reduced pressure above the brake piston 14 will cause the brake piston 14 to be moved upwardly to its braking position under the force of the braking spring 13.

As already indicated, the lifting and lowering operation of the bridge span 1 is performed by successive extensions of the hydraulic drive pistons 7. During the raising action, the piston brake 5 is coupled to the rail 4 by the release of hydraulic pressure from its braking piston 21 (FIG. 7) by valve 22. Span brake is released by the application of hydraulic pressure through valve 23. These brakes 5 and 6 are generally similar to the fail-safe brake 12 used on the hydraulic drive cylinder 8. Thus, as seen in FIGS. 7 and 8, each brake includes a hydraulically movable braking piston 25 which is released by hydraulic pressure and which applies a braking force under the action of compressed springs 26 when the hydraulic pressure in chamber 27 is released. The braking bore is applied to rails 4 through the mechanical action of the conical surfaces 28 of the brake piston 25 and complementary tapered surfaces 29 on the brake shoe 30. Caged ball bearings 31 are preferably positioned intermediate these tapered surfaces to reduce the friction during the braking action.

During the lifting action, the brake 6 attached to the moving brake span 1 or other structural member is in its released position which means that hydraulic fiuid under pressure has been admitted through release inlet 32 to depress the braking piston 25. These pressure is maintained until the bridge span 1 rises to the fully extended position of the hydraulic drive cylinders 8 at which time the hydraulic pressure is released at the inlet 32 permitting the braking springs 26 to move the braking piston 25 to its braking position. As seen in sectional FIG. 8, the brakes 5 and 6 differ from the brake 12 upon the hydraulic drive cylinder 8 as their outer casings 33 have a V-shaped indents 34 for receiving the support sections 35 of the guide rails 4. The central brake shoes 30 and braking piston 25 are cut away so that they have a generally arcuate form to accommodate this changed brake shape. Since the preferred forms of the brake pistons 25 and the brake shoes 30 comprise several arcuate sections, this change may be readily obtained by removing several of these sections from the braking assembly and by altering the shape of outer casing 33 as shown in FIG. 8.

Alternate embodiment of the brake shoe elements FIGS. 9 through 11 illustrate an alternate embodiment of the brake shoes or locking elements. In this embodiment, each of the vertical guide rails 4 has a series of vertically aligned detents or locking holes 40 provided on its surface facing the bridge span 1. In place of the previously described friction brakes, a pair of sprocket wheels 41 are mounted on a common equalizing shaft 42. The shafts 42 are rotatably attached by bearings 43 to the span 1 and by bearings 44 to a piston coupling bracket 45. Suitable housings 46 are provided to protect these sprocket wheels 41. During the part of each lifting cycle where either the piston brake or the span brake is to be locked, the shaft 42 rotation is arrested by the centrally located shaft brakes 47. These brakes 47 may be fail-safe brakes with generally the same design as the brake 12 described above for the drive cylinder 8 or they may be any other suitable hydraulically operated shaft brakes, for example, as described in my above referred to patent. It is preferable that these also have a fail-safe design of the type already described where the brakes are released by hydraulic pressure and are applied whenever this pressure is cut off or fails by suitable continuously acting metal, elastomer or other elastic springs.

Operation Assuming that the design provides for a hydraulic piston rod 7 stroke of 20 feet and that the maximum vertical movement of the span 1 is to be feet, the following cycles are provided. The hydraulic system is preferably provided with pressure in two stages, first by starting up the motor 50 under no load and by then gradually raising the pressure to the required operating value, either by manual or automatic means.

With the controls set for a full 100 foot lift, manual or automatic operation of the valves distributes hydraulic pressure in the system to accomplish the following functions. The cylinder rod 7 is first locked in stationary position by a release of hydraulic pressure from brakes or brakes 47 acting on the equalizing shafts 42. With the hydraulic cylinder rods 7 all held stationary by their brakes 5 or 47, pressure is applied to the hydraulic cylinders 8 and their fail-safe brakes 12 which hydraulic pressure releases the brakes 12 and starts the span 1 rising.

The bridge span 1 rises to its 20 ft. level as limited by the stroke of the hydraulic cylinder piston rods 7 and preferably cushioned stops in the hydraulic cylinder units 8 bring the bridge span 1 to a gradual stop. Pressure is then released at the brakes 6 or 47 on the equalizing shafts 42 located at each end of the movable span 1 to lock the span 1 to the guide rails 4. The controls would then release the locking brake 12 of the cylinder rods 7 and the brakes 5 or 47 for the rod ends and hydraulic pressure would be applied to the double acting hydraulic cylinders 8 to retract the hydraulic cylinder rods 7 in order to prepare for the next twenty foot lifting cycle. The rod retraction would take place at a high speed rate by a large increase in volume of hydraulic fluid flow either by cutting in an additional pump or by a modulating valve control.

The hydraulic cylinder rods 7 would retract to a cushioned position and moving with them would be the brakes 5 on the detect assemblies 41, 42 on which the rod ends are mounted. When the fully retracted position is reached, the position locking brakes 5 or 47 would be applied to lock the rod 7 ends for the next twenty foot lifting cycle.

The previously described cycle would be repeated until the full height of opening is attained and then the reverse process would be used in the controls or performed manually for lowering the span to a fully lowered position.

It will be seen that a relatively simple and effective means has been provided for raising lift bridge spans or other structures over varying distances from a few feet to an almost indefinite height. The hydraulic system disclosed performs this operation with a minimum amount of structure as the novel method described operates on a repeating principal where the lift means may be operated through an appropriate number of repeated cycles to raise the bridge or other structure using successive lifting steps.

In particular, a hydraulic lifting means of this type has been described which is characterized by its reliability and fail-safe features and by the use of a hydraulic control which is adaptable for use with corresponding simple leveling means whereby the structure may be kept horizontal or at any other desired attitude throughout the entire operation.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. Means for vertically moving a structure comprising:

(a) a plurality of vertical rails being spaced from one another and positioned adjacent to said structure;

(b) a hydraulic drive motor for each rail comprising a cylinder and movable piston driven rod, each cylinder being attached to the structure to be lifted;

(c) a first brake mounted on the cylinder adjacent each rail and releasably engaging the rail;

(d) a second brake on the piston rod of each drive motor, each second brake releasably engaging said rails at a point adjacent the point of engagement of the first brake;

(e) means coupled to each of said brakes to engage and disengage the same; and

(f) a supply of hydraulic fluid to raise or lower the hydraulic drive cylinder whereby said structure may be moved along said rails by moving said drive member in one direction while said first brake members are released and said second brake members are applied and moving said drive member in an opposite direction when said second brake members are released and said first brake members are applied.

2. The means as claimed in claim 1 in which said first and second brake members comprise integral resilient means for applying them to said rails and integral hydraulic means for releasing them from said rails.

3. The means as claimed in claim 1 which further comprises brake means on said drive members for releasably engaging said drive member.

4. The means as claimed in claim 1 which further comprises spaced recesses in said rails, at least one of said first and second brake means comprising a sprocket wheel having projections for entering said recesses, means for rotatably mounting said wheel, and a brake for arresting the rotation of said wheel.

5. The means as claimed in claim 4 in which said brake for arresting the rotation of said wheel comprises integral resilient means for applying the brake and integral hydraulic means for releasing the brake.

References Cited UNITED STATES PATENTS 1,648,423 11/1927 Powelson 61-46.50X 2,841,961 7/1958 Lucas 6l-46.5 2,906,100 9/1959 De Long 61 46.5 2,932,486 4/1960 Suderow 254-93 2,944,403 7/1960 Smith 61-46.5 2,969,648 1/1961 Rechtin 6146.5 3,183,676 5/1965 Le Tourneau 61-465 3,398,541 8/1968 Thomas 61-46.5

JACOB L. NACKENOFF, Primary Examiner US. Cl. X.R. 

